1. Field of the Invention
The present invention relates to an electrical connector for a flexible flat cable, and more specifically to an improved electrical connector for flat flexible cables referred to as "FFC" or flexible printed circuit refereed to as "FPC", which ensures a completely inserted condition for the cable when each conductor on the cable is electrically connected to each terminal in said electrical connector.
2. Description of the Prior Art
As is already known in the art, various types of FFC or FPC cables as stated above and many kinds of electrical connectors for connecting the respective conductors on such cables to the respective terminals which have lead wires coupled thereto, or to the respective terminals which are coupled to conductors on printed circuit boards are extensively utilized.
These prior art electrical connectors comprise a connector housing having a plurality of terminals arranged in parallel therein with a flexible flat cable being inserted into an insertion space defined between contact portions of said terminals and an upper wall of said connector housing. Then each of a plurality of flat conductors on the exposed end portion of said flexible flat cable is resiliently held between the upper wall of the connector housing and each of the contact portions of the terminals, thereby completing an electrical connection therebetween.
Although the prior art electrical connectors have an advantage in that they are simple in construction and easy to manufacture, they lead to a significant deficiency in that detachment of the flexible flat cable from the connector is likely to occur because means for preventing such detachment includes the resilient holding force of the terminals. To increase the ability of these prior art connectors to prevent detachment, the force of the terminals on the cable must be increased. But there are problems in increasing this force.
An electrical connector which overcomes the above deficiencies has been proposed in Japanese Utility Model Laid Open No. 129286-1986. As disclosed therein, the electrical connector for a flexible flat cable comprises a connector housing having a plurality of terminals arranged therein at predetermined intervals in parallel, and a connector cover removably mounted on said connector housing and having a pressure blade capable of being inserted into a space defined between an undersurface of an upper wall of said connector housing and a contact portion of each terminal. A flexible flat cable having a plurality of flat conductors arranged thereon at predetermined intervals in parallel is completely inserted through an insertion port of said connector cover into said space. After cable insertion, said pressure blade of the connector cover is pushed into a completely inserted position within said space so that said pressure blade of the connector cover serves to displace each terminal. This causes the flat conductors on said cable to be resiliently held between said contact portion of each terminal and said blade thereby electrically connecting said flat conductors and said contact portions of said terminals.
According to the arrangement as stated above, at the time of insertion of the flexible flat cable, because the contact portion of the terminal is not resiliently pushed against the under surface of the upper wall of the connector housing, the cable is freely inserted into an open insertion space with a low insertion force. The pressure blade causes the downward deflection of the terminal to increase the resilient force thereof, thereby resiliently holding the conductors on the flexible flat cable between the contact portion of the terminal and the pressure blade consequently assuring the completely inserted position for the flexible flat cable.
It is to be noted, however, that in the above connector arrangement, because the flexible flat cable is being held in the completely inserted position only with the resilient force of the terminal, it is desirable to provide the connector with a more efficient means for preventing the detachment of the cable, especially where the electrical connector for connecting the flexible flat cable and the terminal is moved, as for example, where the electrical connector is used with movable parts.